With development of society, requirements for capacity and quality of information in network communication become increasingly high, so does social requirements for broad band videos, multi media services and other real time services based on IP. Those new services take a great deal of bandwidth, which promotes high speed broadband network development in communication field. Compared with a conventional electrical signal transmission network, optical fiber network becomes a main developing direction, because it provides enormous bandwidths, and good load bearing capacities and safe encryption functions. Among many network realization solutions, a network with combination of optical signals and electrical signals is limited by the maximum working speed of electrical devices, and especially limited by the poor processing ability of switching/routing, which results in a bandwidth bottleneck. An all-optical network solution based on optical fiber can break through the bandwidth bottleneck and meet requirements of high speed bandwidth services, because of its high speed, large-capacity transmission and great exchange processing ability.
In an all-optical network, optical information flows are transmitted, exchanged, and routed in a form of light beams, without need of optical-to-electrical and electrical-to-optical conversions. In the all-optical network solution, optical path switches and routers is a crucial optical technical nodes, which are mainly adapted for exchanging and routing optical signals passing through the optical nodes between any optical interfaces.
It is well known that the micro electronic mechanical system (MEMS) processes can be used to manufacture an optical router. For example, a paper by Wood R. L, Madadevan R, and Hill E in the proceedings of the Optical Fiber Communications conference in March, 2002, discloses a two-dimensional matrix optical router based on MEMS. A structural schematic view of the two-dimensional matrix optical router is shown in FIG. 1. The router includes a two-dimensional pop-up MEMS reflector matrix configured in a free space. In the matrix, reflectors located on every matrix node may be started with a rotary pop-up by an electromagnetic deflection control mechanism (not shown in FIG. 1) and be kept stable at a specific deflection angle. When a light beam is transmitted to a node and irradiates on a reflector, the reflector's deflection angle determines a reflection direction of the beam, so that the beam can be selectively transmitted to any other nodes. As shown in FIG. 1, a light beam input from an input end In is sequentially reflected by reflectors 1, 2 . . . 5, and finally output by an output end Out, and thus the light beam is routed from the input end In to the output Out.
However, in the MEMS reflector matrix of the above optical router, the electromagnetic deflection control mechanism of reflectors at each node is complex in structure, resulting in a large size of the router. Besides, it is difficult to accurately control the deflection angle, which may induce a lateral offset error which may be accumulated and amplified after multiple nodes, and further reduce the coupling efficiency of the input light beam.